The invention relates to placement of tubular endoprostheses or stents for body passages, particularly for opening, dilating and maintaining blood vessels and other biological ducts which are at risk of closure due to flaps, dissections, loose vessel debris, etc.
The general use of endoprostheses for such purposes is well known. In one technique a tubular endoprosthesis is mounted over an inflatable balloon of corresponding length, which is part of a disposable balloon catheter. The catheter is inserted into a vessel or duct and guided to the desired site. The balloon is then expanded to expand and permanently secure the endoprosthesis at the site. After this the balloon is deflated and the catheter is withdrawn to complete the placement sequence, and the balloon catheter is discarded. When the region of the blood vessel or duct requires placement over a length greater than the length of a standard prosthesis, often two of the prostheses are placed by their respective balloon catheters in end-to-end relationship with some overlap. This requires two separate placement sequences, requires the use of two disposable balloon catheters, and creates a number of problems both in placement and in use. Other techniques seeking to use long endoprostheses and stents have had drawbacks related to placement or use.